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| author | Jason Evans <jasone@canonware.com> | 2014-09-28 14:43:11 -0700 |
|---|---|---|
| committer | Jason Evans <jasone@canonware.com> | 2014-09-28 14:43:11 -0700 |
| commit | f97e5ac4ec8a5ae7ed74829e6c1bf6ce814947f5 (patch) | |
| tree | 0ffae73077e48d9e51ce7537f3fa1afee39c9763 /include/jemalloc/internal/bitmap.h | |
| parent | 6ef80d68f092caf3b3802a73b8d716057b41864c (diff) | |
| download | jemalloc-f97e5ac4ec8a5ae7ed74829e6c1bf6ce814947f5.tar.gz | |
Implement compile-time bitmap size computation.
Diffstat (limited to 'include/jemalloc/internal/bitmap.h')
| -rw-r--r-- | include/jemalloc/internal/bitmap.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/include/jemalloc/internal/bitmap.h b/include/jemalloc/internal/bitmap.h index 6db4ab7..4ca40ff 100644 --- a/include/jemalloc/internal/bitmap.h +++ b/include/jemalloc/internal/bitmap.h @@ -3,6 +3,7 @@ /* Maximum bitmap bit count is 2^LG_BITMAP_MAXBITS. */ #define LG_BITMAP_MAXBITS LG_RUN_MAXREGS +#define BITMAP_MAXBITS (ZU(1) << LG_BITMAP_MAXBITS) typedef struct bitmap_level_s bitmap_level_t; typedef struct bitmap_info_s bitmap_info_t; @@ -14,6 +15,51 @@ typedef unsigned long bitmap_t; #define BITMAP_GROUP_NBITS (ZU(1) << LG_BITMAP_GROUP_NBITS) #define BITMAP_GROUP_NBITS_MASK (BITMAP_GROUP_NBITS-1) +/* Number of groups required to store a given number of bits. */ +#define BITMAP_BITS2GROUPS(nbits) \ + ((nbits + BITMAP_GROUP_NBITS_MASK) >> LG_BITMAP_GROUP_NBITS) + +/* + * Number of groups required at a particular level for a given number of bits. + */ +#define BITMAP_GROUPS_L0(nbits) \ + BITMAP_BITS2GROUPS(nbits) +#define BITMAP_GROUPS_L1(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(nbits)) +#define BITMAP_GROUPS_L2(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS((nbits)))) +#define BITMAP_GROUPS_L3(nbits) \ + BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS(BITMAP_BITS2GROUPS( \ + BITMAP_BITS2GROUPS((nbits))))) + +/* + * Assuming the number of levels, number of groups required for a given number + * of bits. + */ +#define BITMAP_GROUPS_1_LEVEL(nbits) \ + BITMAP_GROUPS_L0(nbits) +#define BITMAP_GROUPS_2_LEVEL(nbits) \ + (BITMAP_GROUPS_1_LEVEL(nbits) + BITMAP_GROUPS_L1(nbits)) +#define BITMAP_GROUPS_3_LEVEL(nbits) \ + (BITMAP_GROUPS_2_LEVEL(nbits) + BITMAP_GROUPS_L2(nbits)) +#define BITMAP_GROUPS_4_LEVEL(nbits) \ + (BITMAP_GROUPS_3_LEVEL(nbits) + BITMAP_GROUPS_L3(nbits)) + +/* + * Maximum number of groups required to support LG_BITMAP_MAXBITS. + */ +#if LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_1_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 2 +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_2_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 3 +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_3_LEVEL(BITMAP_MAXBITS) +#elif LG_BITMAP_MAXBITS <= LG_BITMAP_GROUP_NBITS * 4 +# define BITMAP_GROUPS_MAX BITMAP_GROUPS_4_LEVEL(BITMAP_MAXBITS) +#else +# error "Unsupported bitmap size" +#endif + /* Maximum number of levels possible. */ #define BITMAP_MAX_LEVELS \ (LG_BITMAP_MAXBITS / LG_SIZEOF_BITMAP) \ |